Fog formed around 2200Z yesterday and to the best of my
knowledge, has persisted ever since. A slight frosty sheen
on some horizontal surfaces but no rime detected. Having
written that, I will report FZFG in the METAR because the
air temperature is below zero Celsius to follow convention
but I will not enter code 49 in the present Synop weather.

As is often the case in these situations, there is a northeast
drift draining off the fields.

SYNOP 11/0850Z (current ob)
03/// 41/01 90403 11004 21004 40307 55000 74644 333 92600=

METAR
EG// 110850Z 04003KT 0150 FZFG VV/// M00/M00 Q//// RED=

Details:
wind... NE, force 1.
visibility... 150m, thickened from 200m an hour ago.
weather... dense fog.
clouds... sky obscured.
dry bulb... -0.4C.
dew point... -0.4C.
RH... 100%.
sea level pressure... 1030.7mb (minor changes).
max temp yesterday... +10.3C.
min temp last night... -0.9C.
24 hour rainfall... 0.1mm (w).

beaufort letters (0750-0850Z)... ffx,Fx.

Nigel (Romsey, Hampshire)
40m amsl